Call to Schedule a Free Consultation


Questioning the Validity of a Blood Test in an Illinois DUI Case

 Posted on June 14, 2022 in DUI

b2ap3_thumbnail_dupage-county-dui-defense-lawyer.jpgDriving under the influence of alcohol (DUI) is penalized by criminal and administrative consequences in Illinois. If you are convicted of DUI, your driver’s license will be revoked and you will not be allowed to drive for the duration of the revocation period. You will also face steep fines and, in some cases, even imprisonment.

However, individuals accused of drunk driving have Constitutional rights, including the right to defend themselves against the charges. One potential defense strategy is to question the validity of blood alcohol test results.

Blood Testing to Determine Blood Alcohol Content

In Illinois, blood testing is frequently used to assess a driver’s intoxication level. Blood testing is not infallible, however. Many different issues can cause blood test results to be inaccurate.

Unlike a roadside breathalyzer test, blood tests are medical procedures. Only qualified individuals may administer a blood test. The blood sample must be taken and stored properly. When blood is not stored properly, it can ferment. Just as a piece of fruit can start to rot and release alcohol, a blood sample’s alcohol level can increase if the sample is fermented. Once fermentation occurs, there is no way to know what the blood sample’s original BAC was.

Rising Blood Alcohol Content

Another issue that can arise during blood testing is a delay between the time the suspect was driving and when he or she was tested. When someone drinks alcohol, their blood alcohol levels slowly rise – even if they stop drinking. The alcohol is absorbed by the intestine and enters the bloodstream. The amount of alcohol in someone’s blood often peaks between 0.5 – 2 hours after drinking. If the person ate food while drinking, peak BAC may not be reached for up to six hours. If substantial time passes between a suspect’s arrest and blood alcohol testing, his or her BAC could have increased significantly from the time of arrest. The suspect’s BAC may have been below the legal limit when he or she was driving.  

Mistakes During Blood Test Administration and Analysis

Errors during the administration or analysis of a blood test can also invalidate results. During blood BAC testing, a substance called potassium oxalate is added to the blood sample to prevent the blood from clotting. Insufficient potassium oxalate can degrade the quality of the sample and cause the test to yield inaccurate results. Even something as simple as using an alcohol wipe on the suspect’s arm before drawing blood can contaminate the sample and cause a false positive result.

Contact a Wheaton Drunk Driving Defense Lawyer

If you or a loved one were charged with driving under the influence, contact Stephen A. Brundage for help. Mr. Brundage is a DuPage County DUI defense attorney with over 30 years of legal experience. He can help you defend yourself against DUI charges. Call 630-260-9647 for a free consultation.


Share this post:
Back to Top